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The following is a summary of “Blood absolute lymphocyte count and trajectory are important in understanding severe COVID-19,” published in the January 2025 issue of Infectious Disease by Paules et al.
Researchers conducted a retrospective study to examine the relationship between absolute lymphocyte count (ALC) trajectory and clinical outcomes, and the factors associated with lymphopenia in severe COVID-19 cases.
They performed a post hoc analysis of the Therapeutics for Inpatients with COVID-19 platform trial using proportional hazards models to examine the relationship between Day (D) 0 lymphopenia (ALC < 0.9 cells/uL), D0 severe lymphopenia (ALC < 0.5 cells/uL), and lymphopenia trajectory from D0 to D5 with mortality, secondary infections, and sustained recovery, analyzed using Fine-Gray models. Logistic regression assessed clinical variables’ relationship with D0 lymphopenia or its trajectory.
The results showed that D0 lymphopenia (1426/2579) and severe lymphopenia (636/2579) were linked to higher mortality (aHR 1.48; 1.08, 2.05, P = 0.016 and aHR 1.60; 1.20, 2.14, P = 0.001) and reduced recovery (aRRR 0.90; 0.82, 0.99, P = 0.033 and aRRR 0.78; 0.70, 0.87, P < 0.001, respectively). Participants with persistent D5 lymphopenia had higher mortality and secondary infections, while those with persistent or new lymphopenia had poorer recovery compared to those without lymphopenia. Persistent and new lymphopenia were associated with older age, male sex, prior immunosuppression, heart failure, aspirin use, normal body mass index, and biomarkers of organ damage (renal and lung) and immune dysfunction (elevated IL-6 and viral nucleocapsid antigen). Similar findings were observed for severe lymphopenia.
Investigators concluded the persistent or newly developed lymphopenia during hospitalization, was linked with severe COVID-19 outcomes, underlying the causes of lymphopenia to improve disease management strategies.
Source: bmcinfectdis.biomedcentral.com/articles/10.1186/s12879-024-10428-7
